Controlling means for refrigerating apparatus.



J. H. COESFELD.

CONTROLLING MEANS FOR REFRIGERATING APPARATUS.

APPLICATION FILED OCT. 30. I916.

1 270,928. Patented July 2, 1918 JHtCoesrsg. o 1n uewto'z.

(Brunet U ITED STATES PATENT OFFICE.

JOHN H. COESFELD, OF OMAHA, NEBRASKA, ASSIGNOIt '10 BAKER ICE MACHINE COM- PART, OF OMAHA, NEBRASKA, (A CORPORATION OF NEBRASKA.

CONTROLLING MEANS FOR REFRIGERATING APPARATUS.

Specification of Letters Patent.

Patented July 2, 1918.

Application filed October 30, 1916. Serial No. 128,598;

To all whom it may concern:

Be it known that I, JOHN H. Consrnnn, a citizen of the United States, and a resident of Omaha, in the county'of Douglas and State of Nebraska, have invented certain new and useful Improvements in Controlling Means for Refrigerating Apparatus,

of which the following is a" specification.

vMy invention relates particularly to devices for automatically controlling refrigcrating mechanism employing a motor- .driven compressor for a volatile refrigerant such as anhydrous ammonia. It is the object of my invention to provide a thermostatic device adapted to be placed in a refrigerating chamber and connected with an automatic switch controlling the motor which drives the compressor, so as to start the motor when the temperature of the chamber risesto a predetermined degree and to stop-the motor when the temperature is reduced to a predetermined degree; and to associate with the thermostatic device a pressure-actuated device adapted to actuate the thermostat so as to stop the motor when the pressure of the refrigerant becomes ex-" cessive, regardless of the temperature, of the excessive pressure occurs. Thus my invention provides a combined temperature-andpressure-actuated means for controlling the operation of an automatic. switch.

In the accompanying drawings, Figure '1 is a front elevation of the temperature-andpressure-actuated device provided by my invention, Fig. 2 is a side view of the same,

and Fig. 3 is. a diagrammatic view illustrating the use thereof in an automatic refrigerating apparatus. 7 H

In the illustrated" embodlment of my controlling device I provide a plate 1, preferably of insulating material, which is disits upper and lower ends, as shown. Near "0!1B of the upper corners 'of the plate 1 a shouldered stud 3 is extended through an opening therein, the rearward end of the stud being threaded and'provided with nuts 4 and 5, as represented in' Fig. 2. The front end of the stud is slottedto receive the inner end of a spiral'coil 6 made of a metal "band or ribbon composed of twolayers-of metal of different expansibility, whereby variations of temperature tend to cause movements of the outer end of the coil proportional to the temperature changes. Secured.

to the outer end of the coil 6, and extending downwardly therefrom, is a fiat bar or arm 7, the same preferably being welded to the material of the coil soas to be substantially integral therewith. The lower end of the I arm 7 dips into a cup 8 secured to the plate 1 'near the lower edge thereof, and said end of the arm is preferably made wider than the upper portion thereof, as indicated by dotted lines in Fig. 2. The cup 8 is filled with a liquid such as a heavy oil, of which the viscosity is such as to suppress oscillatory movements of the arm caused by vibra-' t1on or jarring of the support on which the plate 1 is mounted. Above the cup 8 at opposite sides of the thermostat-arm 7 there are mounted on the plate lblocks 9 through which are passed screws 10 and 11, said screws being provided with locknuts 12 and 13 for holding them in adjusted relations to the blocks. On the inner ends of the screws l0 and 11 carbon contact-blocks H and C are mounted as shown, said contact-blocks v .being adapted for engagement by the arm refrigerating chamber at the time when the 7 as the same is moved, respectively, by increases and decreases of temperature of the coil 6- 7 a 1 Near the upper'end of the plat 1,-at the side opposite the stu'd 3, a block 14. is mountte'said block is se- 4 ed fixedlyithereon' and cured o'n'end o a -U-shaped Bourdon ieb .1.5...s11c a ismmmon1 used for to sureegages. The bldck 1 1 is hollow, and forms. a connection between the tube 15 and rangement'is such-that, by movement of the tube 15 resulting from pressure therein, the

block 20 is engaged with the arm "(and gushes the same over toward the contactlock C. The coil 6 being yieldable and ex- 'erting a relatively slight actuatindgjiforce y acupon the arm 7, said arm may be rea D tuated by the pressure-tube irrespectlve of any tendency of the coil to move it othera pipe 16 which extends back through the plate 1. On the free end' of the tube thereis carried a head 17 -thi'ough which is A typical automatic refrigerating apparatus, employing the above described controlling device,'is represented diagranunatr cally in Fig. 3. As shown in said figure, the controlling device is placed within a refrigerating-chamber inclosed by a wall 21, the chamber having suitable coils 22 in the upper part thereof, wherein the liquid ammonia or the like is expanded to cool the chamber. A compressor 23 for the refrigerant is driven by an electric motor 24. The intake or suction pipe 25 of the compressor is connected with the coil 22 so as to receive the expanded refrigerant therefrom, said Pipe having connected therein a check-valve 26, and also being connected with a suitable pressuregage 27. The discharge-pipe 28 extends from the compressor to a suitable condenser 29 wherein the eompressed'gaseous refrigerant is cooled by water so as to become liquefied, and the liquid refrigerant passes from the condenser to a receiver 30 through a pipe 31. From the. receiver a pipe 32 extends to the expansion-coil 22, the How of the liquid to said coil being controlled by a suitable valve 33. Water is supplied to the condenser through a pipe 34 and is discharged therefrom through a pipe 35. From the discharge-pipe 28 of the compressor, a

branch-pipe 36 is extended into the refrigcrating-chamber and connected with the pipe 16 which communicates with the pressure= tube 15 of the controlling-device. The water-supply to the condenser is controlled by a valve 37 of which the operation is dependent upon the pressure in a pipe 38 branching from the pipe 36. A pressuregage 39 is also connected with the pipe 36. Electric power for the motor 24 is received from the mains or supply-lines 40 which are connected with a main-switch 41. The control of the motor, for automatically starting and stopping the same in accordance with the requirements of the refrigerating mechanism, is effected directly by an electrically-actuated switch which may be of the general type represented in the drawing. In said switch there is a solenoid-coil 42, by energization of which a plunger or core 43 is actuated to move an oscillating member-44 alternately between two positions. The member 44 is connected with reciprocatable switch-blades 45- adapted'to engage contacts 46 at one position of the member 44, and to be disengaged from said contacts by movement of the member 44 to its other position. The blades 45 and contacts 46 are suitably connectedby wires 47 ai1d48 with the main-switch 41 and the motor, so

that the motor-circuit isclosed when said blades engage said contacts, and is opened when. the blades are disengaged from said contacts. One terminal of the coil 42 is connected with one of the wires 47 and the other terminal of said coil is connected with the oscillating member 44. The member 44 engages a contact 49 when the motor-circuit is closed, and engages a contact 50 when the motor-circuit is opened. The contacts 49 and 50 are connected, respectively, by wires 51 and 52, with the contacts C and H of the controlling device in the refrigerating-chamher, and the arm 7 of said device is connected by a wire 53 with the common or IBtlll'lb wire 54 of the motor-circuit, so that by engagement of said arm 7 with the contacts (3 and H control-circuits may be established through the switch-actuating coil 42.

The operation of the describedmechanism will be obvious to those skilled in the art. The screw 18 is so adjusted that under normal operating conditions of the apparatus the block 20 will not engage the arm 7, and the latter will be actuated solely by the coil 6; but the adjustment is also made such that, should the pressure of therefrigerant exceed a determined maximum, then the block 20 will engage the arm 7 and actuate the same regardless of any tendency of the coil 6 to move said arm toward the contact H. Thus, under normal operating conditions of the apparatus, the motor is controlled by the thermostat, the arm 7 moving into engagement with the contact C when the temperature is suficiently low, and moving into engagement with the contact H when the temperature of the refrigerating-chamber rises to a predethrough the wire 52, contact 50, member 44,

and coil 42, which energizes the latter andmoves the switch-blades 45 into engagement with the contacts 46, thus closing the motorcircuit and starting the operation of the compressor. The movement of the member 44 opens the control-circuit at the contact 50,,

but establishes an alternative connection at the contact 49, so that when the temperature of the refrigerating-chamber is sufiicient-ly vcontrol-circuit at the contact If for any reason, such as a failure of the water-supply reduced, and the arm 7 is thus moved into a,

for cooling the condenser, the pressure of the refri erant becomes excessive said pressure wil cause movement of th such as to engage the block 20 with the thermostat-arm 7, thereby first preventing 'said arm from moving into g gement with the contact H 'and finally moving said 'arm into engagement with the contact C.

e tube 15 I Thus, when the excessive pressure occurs, if

the motor is not in operation it is prevented from being started by a rise of temperature in the refrigerating-chamber, and if the motor is in operation it Will be stopped by the abnormal pressure, regardless of the temperature of the refrigerating-chamber at the time.

Any of the ordinary and well-known forms of automatic electrically-actuated switches may be used in connection with my controlling device, the specific form of switch herein shown and described being intended to be merely illustrative of the 'ty e of switch that may be employed; and it W111 be understood that many other variations of the described refrigerating apparatus are possible, and that my controlling device is not limited to use with the particular apparatus herein referred to.

Now, having described my invention, what I claim and desire to secure by Letters Patent is: v Y

1. Controllingmeans for refrigerating apparatus, comprising a pair of contacts, an arm movable between the same, thermostatic means tending to move said arm in accordance with temperature-variations, and pressure actuated means for moving said arm -and a pressure-actuated with said movable member and adapted to irrespective of the tendency of the thermostatic means to actuate the same.

2. In a refrigerating apparatus, means for compressing a volatile refrigerant, an electric motor for driving said compressing means, an electrically-actuated switch con trolling said motor, control-circuits for said switch, a movable member connected in said control circuits, temperature responsive means normally actuating said member to open and close said control-circuits, and means actuatedby pressure of the refrigerant for moving said member irrespective of the temperature-responsive means.

3. Controlling means for refrigerating apparatus, comprising electrical control-circuits, a movable member connected in said circuits, yieldable thermomotive means connected with said member and tending to move the same to close the control-circuits in accordance with temperaturevariations, element engageable actuate said member to position for closing one of the control-circuits irrespective of any tendency of the thermomotive means to move said member otherwise.

J. H. OOESFELD. 

